Everyone’s heard of antibiotics. Most (if not all) people would have been prescribed with antibiotics by their health practitioner at some point in their lives to stave off an infection.
But have you ever delved deeper into the subject of bacterial infections, antibiotics, antibacterials and antibacterial resistance? It can get quite interesting…and also quite concerning!
Let’s begin at the beginning. What are bacteria?
Bacteria (the plural of bacterium) are single-celled microscopic organisms and they come in many shapes. They have been around for over 3.5 billion years and exist absolutely everywhere. While some bacteria are pathogenic, meaning that they can cause disease, most are harmless or even beneficial. In fact, less than one percent of bacteria are responsible for diseases in humans.
What causes a bacterial infection?
Bacterial infections are caused by the transmission of harmful or pathogenic bacteria. Once they are inside the body, they multiply, thrive and result in an infection. Bacterial infections can be transmitted by different means: from other people or animals, through the environment, or from contaminated food and drink.
Following on from that, can you explain what the term ‘antibacterial’ means?
An agent is considered to be ‘antibacterial’ when it can kill bacteria or inhibit their ability to grow and spread.
Is there a difference between ‘antibacterials’ and ‘antibiotics’ or are they essentially the same thing?
Antibacterials and antibiotics are two terms that are often used with the same meaning – that is, able to kill or inhibit bacteria. However, there are some differences in their precise meaning.
For example, antibacterials only target bacteria (not virus or fungi) and this includes medicinal antibiotics but can also refer to other non-medicinal things like soaps, disinfectants and detergent.
An antibiotic is typically given as a medication to treat a bacterial infection, but some may target other microorganisms as well (e.g. protozoans).
How are antibiotics effective against bacterial infections?
Different antibiotics work in different ways and target different parts of the bacteria. For example, penicillin attacks the bacterial cell wall, causing structural damage and kills the bacteria. While erythromycin or tetracycline inhibit protein synthesis and stop bacterial growth.
Can antibiotics be used to treat a virus?
No, antibiotics are not useful against viruses.
Viruses are different to bacteria in many ways and lack the components that antibiotics target. For example, bacteria have cell walls which can be attacked by antibiotics such as penicillin, however viruses do not have a cell wall. Many viruses have a protein coat around them which means penicillin or similar antibiotics are not effective against these viruses.
What is meant by ‘antibacterial resistance’?
Antibacterial resistance occurs when bacteria adapt and develop the ability to resist an antibacterial or antibiotic that was once deemed an effective treatment for an infection.
Bacteria can either be completely resistant to the effect of the antibiotic, or higher concentrations may need to be used to kill or inhibit the bacteria.
What causes antibacterial resistance?
Antibacterial resistance usually occurs when there is a change in the cellular characteristics of the bacteria, which means that specific antibiotics can no longer recognise their target. Like a lock and key – if the bacteria change the shape of the lock – then the key no longer fits.
In many cases antibiotic resistance is acquired. Genes responsible for antibiotic resistance, for instance, can be transferred between different species of bacteria. This means that bacteria once susceptible to an antibiotic have now acquired a way to overcome its effect.
Resistance can also be spontaneous and occur due to mutations in the genes that encode the antibiotic target.
How can taking antibiotics contribute to antibiotic resistance?
When antibiotics are used, some bacteria will die. However, there may be resistant bacteria that survive and multiply. The more antibiotics are used, greater is the chance that bacteria become resistant and can then spread to other people.
Also, antibiotics often eliminate other microorganisms in addition to pathogens. This enables resistant bacteria to thrive. In a somewhat harmful ripple effect, these resistant bacteria can then also share their genetic elements with other bacteria.
Is the global issue of antibacterial resistance increasing, and what is accelerating the issue?
The global issue of antibacterial resistance is becoming more challenging and there is a constant race between scientists discovering and developing new antibiotics, and the bacteria mutating and adapting to the current treatments.
Antibacterial resistance is expedited by the overuse of antibiotics worldwide. In many countries, the usage of antibiotics is not regulated, which means they are easily accessible without a prescription and that, in turn, heavily contributes to overuse.
Why should the general public care about antibiotic resistance?
The recent emergence of many super-bugs such as Methicillin-Resistant Staphylococcus aureus (MRSA), Vancomycin-Resistant Enterococci, ESBL-Producing Enterobacteriaceae and drug-resistant Neisseria gonorrhoeae, has made many public health organisations refer to antibiotic resistance as an urgent threat to public health. In the worst case scenario, people have died from infections that can no longer be treated by antibiotics.
Antibiotic resistant infections are more difficult to treat, which means that patients may be sick for longer, require more expensive medications or medications with increased side effects, and they may need to be treated in hospital. The biggest concern in the immediate future is that we will no longer have effective antibiotics to treat infections.
Is there anything that we, the general public, can do to stop the acceleration of antibacterial resistance?
The general public should recognise the seriousness of antibiotic resistance and do their bit to prevent the issue from accelerating further.
As the saying goes, prevention is better than cure, so the more we do to prevent the spread of harmful bacterial infections, the less we would require the use of antibiotics, which will help reduce antibacterial resistance. Simple ways to reduce disease transmission have become all too familiar of late – basic hygiene practices like washing our hands, covering our mouth when we cough, and staying home if we’re unwell all helps reduce the spread of infections.
It’s also important to avoid the misuse/overuse of antibiotics and heed the advice of health professionals. This crisis requires coordinated efforts from health professionals and the general public to ensure regulations/policies are implemented accordingly.
What can health professionals do to help stop the acceleration of antibacterial resistance?
Health professionals can provide clear and simple information to help educate their patients on the usage and importance of antibiotics. This should include the significance of completing the prescribed dose, explanation of problems involved in the misuse of these drugs and providing information/brochures when necessary.
Can you explain the Institute’s research approach to bacterial infections?
Many bacteria interact with human cells via sugars (also called glycans or carbohydrates) on the surface of either the bacteria or the human cell. These interactions are often a critical first step to an infection. At the Institute for Glycomics, we focus on characterising these sugar-based interactions and develop new drugs or vaccines that can block these interactions and prevent infection.
How is your research addressing the issue of antibacterial resistance?
Our research team focuses predominantly on the bacteria Neisseria gonorrhoeae which causes the sexually transmitted infection (STI) gonorrhoea. N. gonorrhoeae has become resistant to almost every antibiotic used to treat it since the 1940s and there is now a global health concern that gonorrhoea may become untreatable in the near future.
According to the World Health Organization, gonorrhoea represents 78 million of the estimated 357 million new cases of STIs which occur globally every year.
This disease affects both men and women, however if left untreated, gonorrhoea can lead to pelvic inflammatory disease (PID) in women, which can cause infertility. Concerningly, many cases of gonorrhoea present with no symptoms and are therefore left undiagnosed and untreated, leading to further transmission and greater health complications in the future.
Here at the Institute for Glycomics, we have been investigating options for new antibiotics and are also focused on developing a vaccine to prevent N. gonorrhoeae infection from occurring in the first place.
ABOUT THE AUTHORS
Professor Kate Seib has international standing in the fields of vaccine development and bacterial virulence mechanisms, with a particular focus on the pathogenic Neisseria, where her research program aims to discover and characterise novel drugs and vaccine targets. Specifically, combatting multi-drug resistant gonococcal infections. Professor Seib and her research group are currently focused on understanding the processes involved in host colonisation and disease, with the aim to identify therapeutic and vaccine targets of bacterial pathogens, including: Neisseria gonorrhoeae (gonorrhoea and infertility), Neisseria meningitidis (meningitis and sepsis), Moraxella catarrhalis and non-typeable Haemophilus influenzae (middle-ear infection).
Dr Taha has expertise in molecular microbiology and protein biochemistry. His research focuses on mucosal pathogens such as Campylobacter jejuni, Vibrio cholerae, Moraxella catarrhalis and Neisseria gonorrhoeae. Taha has worked on transducer-like proteins which are believed to play a vital role in survival and virulence of Campylobacter jejuni. Currently, he has taken up projects to understand the pathogenicity of Moraxella catarrhalis which is responsible for middle ear infections and exacerbations of chronic obstructive pulmonary disease; and to identify and characterise potential vaccine candidates of Neisseria gonorrhoeae which causes sexually transmitted infection and infertility.
Valentin Slesarenko is a research assistant working in Professor Seib’s research group. He is a graduate student of Biomedical Sciences, specialising in microbiology, biochemistry and immunology.
Currently, Valentin is participating in research around Neisseria gonorrhoeae, with the aim to identify potential vaccine targets and potentially prevent complications such as infertility, caused by the sexually transmitted infection.